Abstract: TH-PO0317
Single Glomerulus Proteomics: A GLIMPSE into Crescentic Glomerulonephritis
Session Information
- Glomerular Diseases: Omics
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Merchant, Michael, University of Louisville School of Medicine, Louisville, Kentucky, United States
- Biederman, Laura, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Barati, Michelle T., University of Louisville School of Medicine, Louisville, Kentucky, United States
- Gaweda, Adam E., University of Louisville School of Medicine, Louisville, Kentucky, United States
- Cummins, Timothy, University of Louisville School of Medicine, Louisville, Kentucky, United States
- Wilkey, Daniel Wade, University of Louisville School of Medicine, Louisville, Kentucky, United States
- Li, Hong, UofL Health Brown Cancer Center, Louisville, Kentucky, United States
- Hata, Jessica Lynn, Carolinas Pathology Group PA, Charlotte, North Carolina, United States
- Dougherty, Julie, Nationwide Children's Hospital, Columbus, Ohio, United States
- Stojkic, Ivana, Nationwide Children's Hospital, Columbus, Ohio, United States
- Wenderfer, Scott E., The University of British Columbia, Vancouver, British Columbia, Canada
- Hidalgo, Guillermo, Hackensack Meridian Health Inc, Edison, New Jersey, United States
- Klein, Jon B., University of Louisville School of Medicine, Louisville, Kentucky, United States
- Gaut, Joseph, Washington University in St Louis School of Medicine, St. Louis, Missouri, United States
- Smoyer, William E., Nationwide Children's Hospital, Columbus, Ohio, United States
Background
Gaps in understanding the molecular mechanisms of glomerular pathology limit the development of targeted treatments. We hypothesized that the proteome of a single glomerulus compared within and across biopsies would reveal critical pathophysiologic pathways.
Methods
Our approach integrated whole-slide biopsy evaluation by renal pathologists with high-resolution proteomics. Using laser capture microdissection (LCM), we isolated crescentic (CR) and non-crescentic (NCR) glomeruli from patients with IgA nephropathy (IgAN) and pauci-immune (PI) glomerulonephritis (GN). These individual glomeruli were analyzed via a Data-Independent Acquisition (DIA) workflow, with proteomic differences determined through linear modeling and adjusted for etiology and histological annotation. Biomarkers were selected using statistical significance (q<0.05 & |Log2FC| >0.5), informatic modeling, and imaging mass cytometry (IMC) to confirm protein abundance and spatial localization.
Results
Crescents (n=12) were evaluated for karyorrhexis (7/12), endocapillary hypercellularity (1/12), necrosis (6/12), capsular rupture (0/12), and neutrophils (0/12). Proteomic analysis of 23 glomeruli (12 CR and 11 NCR) by this LCM-DIA workflow identified approximately 2,197 proteins per glomerulus at a 1% FDR, reaching up to 2,708 proteins from a single 5 μm cross-section. We successfully quantified 2,118 proteins across 80% of all samples, identifying 178 proteins that differentiated CR from NCR adjusting for GN and necrosis. This workflow enabled the distinction of intra- and inter-biopsy differences and signatures associated with glomerular necrosis. Pathway analysis defined broad thematic shifts in the extracellular matrix, integrin/adhesion, macrophage-driven inflammation, ribosome translation, and ER stress. Notably, pathways specific to crescent formation remained consistent across both IgAN and PI GN. Furthermore, IMC demonstrated that the spatial distribution of enriched proteins could distinguish between cellular, fibrocellular, and fibrous crescents.
Conclusion
In conclusion, this novel method demonstrates the power of integrating single-glomerulus proteomics, histopathology, and spatial analysis by IMC. Together, this integrated approach demonstrated the ability to identify cell signaling pathway enrichment linked to pathological findings, which could be applied to discover mechanistic pathways and therapeutic targets in future studies.
Acknowledgment
We gratefully acknowledge the patients and their families who support translational research. We also acknowledge the clinical divisions, clinical departments and instutituions of authors for their continued support of biomedical research. MM & LB, and JG & WS are equal contributing authors.